Computing 205/406 & IT8

Tutorial #16

1. How would you request a router to return the actual values of the objects ipForwarding, icmpInEchoes and tcpMaxConn? Give solutions using each of the get and get-next commands.

2. The following is a diagrammatic view of portion of a table (ifTable) in the interfaces portion of the standard MIB, edited to fit the page. The table consists of a sequence of ifEntry elements. Values shown are from the router r-bgowan at Bendigo.

   

   1. Describe interface 3 on this router.
   2. What would be the structure of an SNMP get-request to discover the speed, in bps, of interface 1.
   3. What value would be returned by get-next(...ifSpeed.2)?

3. Why do SNMP proponents use the expression "powerful get-next"? In other words, what problem does the get-next operation solve very elegantly?

4. (Philosophical question) What is the purpose of the SNMP portion of the MIB?

Practical exercises:

• Use tkined to discover routes to selected Internet hosts and display the network map. Investigate some of the (very powerful and fully industrial strength) functions available in tkined.

• Use the CMU SNMP utilities in the directory /usr/local/snmp on our Unix systems. Try fetching the MIB variable system.sysDescr.0 from various departmental systems, and thus learn which are running SNMP.